The Economics and Reliability of Multifunction Devices

The widely prevalent assumption that device failure rates are multiplied when two or more functions are incorporated In a single enclosure is examined with respect to actual experience on single-element vs multiple-element electron tubes. The feasibility and economics of multi-element structures are considered in the light of the recent trend toward greater and greater complexity of device combinations. The natural limits to this trend are predicted by extrapolating known factors related to spread of characteristics, random catastrophic failures, and life. Some of the most recent examples of this philosophy are described and discussed in comparison to earlier versions providing similar functional performance.